Conventional underground mining wherein people and equipment are lowered underground via a mine shaft is perilous and unhealthy; in addition, many energy resources are imbedded too deep in the ground, making them inaccessible to manpower and to mining equipment. The advantages of pyrolyzing a resource such as coal underground in-situ are several. The main advantage is the recovery of volatile matter containing a H2 rich gas which is most suitable for many valuable applications. Some of the other advantages comprise the elimination of costly surface mining, the elimination of men and machines lowered underground to perform the dangerous operation of digging the resource, reaching valuable and abundant energy resources that are inaccessible, essentially doing away with surface damage to land, drastically reducing the production of pollutants, and saving lives.
One method of in-situ gasification of coal, known as Underground Coal Gasification, comprises the conversion of the coal into gases by making use of underground combustion wherein the very valuable volatile matter in the coal is burned with the carbon, resulting in a poor quality gas. Some other disadvantages of such underground coal gasification using combustion present the following problems;                Poor quality recovered gas by virtue of high N2 and low H2 content;        Groundwater contamination;        Excessive cavity temperatures;        Unsteady state, making it difficult to control;        Wide thermal gradients;        Land subsidence in case of shallow resource seams; and        Underground generation of greenhouse gas such as CO2.        